Methacrylic resin has excellent optical characteristics, such as transparency, and weather resistance, and molded articles thereof have a beautiful appearance; thus, methacrylic resin has been traditionally used in a variety of applications such as illumination equipment, display devices such as signboards, optical members such as components of displays, interior appliances, building parts, electronic and electric parts, and medical equipment. In contrast, since methacrylic resin is a brittle material, it has been difficult to directly use methacrylic resin in applications requiring flexibility, elasticity, impact resistance, and plasticity.
A variety of approaches have been made to enhance the flexibility, elasticity, impact resistance, and plasticity of methacrylic resin.
Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 10-168271), for example, discloses a resin composition, in which impact resistance is mainly enhanced as a result of mixing acrylic resin with a block copolymer containing a highly syndiotactic poly(alkyl methacrylate) block.
Patent Literature 2 (Japanese Unexamined Patent Application Publication No. 2000-154329) discloses a resin composition produced as a result of mixing acrylic resin with an impact resistance enhancer that is a block copolymer composed of a methacrylic polymer block and an acrylic polymer block.
Patent Literature 3 (Japanese Unexamined Patent Application Publication No. 2003-277574) discloses a resin composition which is produced as a result of mixing an acrylic thermoplastic elastomer with methacrylic resin and which exhibits weather resistance, plasticity, and mechanical properties in a well-balanced manner.
Patent Literature 4 (International Publication No. WO2010/055798) discloses a resin composition which is produced as a result of mixing acrylic resin with multiple acrylic block copolymers and which exhibits excellent transparency and moldability in a wide range of structures.
Patent Literature 5 (Japanese Unexamined Patent Application Publication No. 2006-124724) discloses a resin composition which is produced as a result of adding a block copolymer containing an acrylic polymer block to a thermoplastic resin for dynamic crosslinking and which exhibits excellent thermal resistance and oil resistance.
Each approach, however, cannot provide sufficient transparency; hence, development of a resin composition not only exhibiting flexibility, elasticity, impact resistance, and plasticity but also exhibiting excellent melt flowability and injection moldability while transparency inherent to methacrylic resins is maintained has been demanded.